/**
 * 年月日显示 _da
 */
function ymd_bind_id(Y,M,D, yearVal, monthVal, dayVal){
     Y_id=Y;
     M_id=M;
     D_id=D;
     strYYYY = document.getElementById(Y_id).outerHTML;
     strMM = document.getElementById(M_id).outerHTML;
     strDD = document.getElementById(D_id).outerHTML;
     MonHead = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    
     //先给年下拉框赋内容
    var y = new Date().getFullYear();
    var str = strYYYY.substring(0, strYYYY.length - 9);
    for (var i = (y - 80); i < (y + 2); i++) //以今年为准，前30年，后30年
    {
        str += "<option value='" + i + "'> " + i + " 年" + "</option>\r\n";
    }
    document.getElementById(Y_id).outerHTML = str + "</select>";
    //赋月份的下拉框
    var str = strMM.substring(0, strMM.length - 9);
    for (var i = 1; i < 13; i++) {
        str += "<option value='" + i + "'> " + i + " 月" + "</option>\r\n";
    }
    document.getElementById(M_id).outerHTML = str + "</select>";
    if ( yearVal) {
      document.getElementById(Y_id).value =yearVal;
    }
    //console.log(yearVal);
    if ( monthVal) {
      document.getElementById(M_id).value =monthVal;
    }
      
    //document.form1.YYYY.value = y;
    //document.form1.MM.value = new Date().getMonth() + 1;
    var n = MonHead[new Date().getMonth()];
    if (new Date().getMonth() == 1 && IsPinYear(YYYYvalue)) n++;
    writeDay(n); //赋日期下拉框
    //document.form1.DD.value = new Date().getDate();
    if (dayVal) {
      if ( yearVal != undefined) {
        document.getElementById(D_id).value =dayVal;
      }
    }
    
}
function YYYYMM(str) //年发生变化时日期发生变化(主要是判断闰平年)
{

    var MMvalue = document.getElementById(M_id).options[document.getElementById(M_id).selectedIndex].value;
    if (MMvalue == "") {
      document.getElementById(D_id).outerHTML = strDD;
        return;
    }
    var n = MonHead[MMvalue - 1];
    if (MMvalue == 2 && IsPinYear(str)) n++;
    writeDay(n)
}
function MMDD(str) //月发生变化时日期联动
{
    var YYYYvalue = document.getElementById(Y_id).options[document.getElementById(Y_id).selectedIndex].value;
    if (str == "") {
      document.getElementById(D_id).outerHTML = strDD;
        return;
    }
    var n = MonHead[str - 1];
    if (str == 2 && IsPinYear(YYYYvalue)) n++;
    writeDay(n)
}
function writeDay(n) //据条件写日期的下拉框
{
    var s = strDD.substring(0, strDD.length - 9);
    for (var i = 1; i < (n + 1); i++) s += "<option value='" + i + "'> " + i + " 日" +
"</option>\r\n";
    document.getElementById(D_id).outerHTML = s + "</select>";
}
function IsPinYear(year) //判断是否闰平年
{
    return (0 == year % 4 && (year % 100 != 0 || year % 400 == 0))
}